1. Field of the Invention
The present invention relates to a communication system which is constituted so that plural repeating installations, to which one or more node terminals are connected, are connected via data transmission lines, and in which data are exchanged between the node terminals, between the repeating installations or between the node terminals and repeating installations, and more specifically relates to a communication method and communication system in which, for example, even when data are exchanged between node terminals belonging respectively to different repeating installations, communication data can be transmitted securely to a destination node terminal specified by an originating source node terminal.
2. Description of the Related Art
Conventionally, a communication system, which is constituted so that plural repeating installations, to which one or more node terminals are connected, are connected via data transmission lines and in which data are exchanged between the node terminals, between the repeating installations or between the node terminals and repeating installations, are generally known.
In the above conventional communication system, when communication data are transmitted from an originating source node terminal to a destination node terminal, communication path management generally adopts the central management method using a central management device.
As for the central management method, a central management device connected with a communication system always monitors use/free state of plural data channels owned by respective repeating installations. At this time, when a node terminal connected to a repeating installation generates a transmission request of communication data, accordingly the repeating installation transmits a use request of the data channel to the central management device. Then, the central management device successively searches plural communication paths from the originating source node terminal to the destination node for data channels which are free or can be changed into a free state so as to allocate the searched data channels to the repeating installations which transmitted the use request. As a result, The communication paths from the originating source node terminal to the destination node terminal can be secured, and the communication data can be transmitted securely from the originating source node terminal to the destination node terminal along the communication paths.
However, according to the communication path management method in the conventional communication system, in the case where data are exchanged between node terminals, for example, every time a node terminal connected with a repeating installation makes a transmission request of communication data, the repeating installation connected to this node terminal transmission a use request of a data channel to the central management device, and accordingly the central management device successively searches plural communication paths from an originating source node terminal to a destination node terminal for data channels which are free or can be changed into the free state, and allocates the searched data channels to the repeating installations transmitting the use request. Since this complicated process should be performed, there arises a problem, which should be solved, such that time required for securing the usable communication paths becomes comparatively long.
The present invention is devised in view of the above circumstances, and it is an object of the present invention to provide communication method and communication system in which instead of the central management of communication paths between repeating installations using a conventional central managing device, another path information where use/free state of plural channels of repeating installations comprised in communication device received from the repeating installations other than a repeating installation itself and use/free state of channels corresponding to one or more node terminal connected with the repeating installation itself are compared and referred to, path information of input-output data inputted/outputted into/from the repeating installation itself is decided, and allocation of communication channels for the input-output data is managed individually and dispersively so that processing load due to the path management on respective installations is reduced and processing time required for the path management in the repeating installations is shortened, and as a result, even in the case where data are exchanged between node terminals belonging respectively to different repeating installations, the communication data can be transmitted securely from an originating source node terminal to a specified destination node terminal.
It is another object of the present invention to provide a communication method and communication system in which a path request repeating installation requesting transmission of communication data in the plural repeating installations selects definite paths through which the communication data pass based on common free paths between path information of the respective repeating installations, which are obtained by referring to path information containing free state of output side paths of the repeating installations existing within a request path range from an originating source to destination of the communication data, and transmits the definite path information containing the selected paths to the repeating installations existing within the request path range, whereas the respective repeating installations existing within the request path range revise the respective path information based on the received definite path information so that when pass paths for the communication data are secured, the communication procedure is simplified, and as a result, even in the case where data are exchanged between node terminals belonging respective to different repeating installations, the communication data can be transmitted securely from an originating source node terminal to a specified destination node terminal.
In order to solve the above problems, a first aspect of the invention provides a communication method used in a communication system arranged by connecting plural repeating installations, to which one or more node terminals are connected, via a data transmission line, said communication method exchanging data between the node terminals, between the repeating installations or between the node terminals and repeating installations, said communication method comprising the steps of:
comparing and referring, in each repeating installation, to another path information, where use/free state of plural channels of the other repeating installations other than the repeating installation itself is described, comprised in communication data received from the other repeating installations and use/free state of channels corresponding to the one or more node terminals connected with the repeating installation itself; and
deciding, in each repeating installation, path information of input-output data inputted/outputted into/from the repeating installation itself;
whereby each repeating installation individually and dispersively manages allocation of communication channels of the input-output data.
According the first aspect, instead of a central management of communication paths between the repeating installations using a conventional central managing device, in the plural repeating installations, a repeating installation compares and refers to another path information where use/free state of plural channels of the other repeating installations is described comprised in communication data received by the other repeating installations other than the repeating installation itself and use/free state of channels corresponding to the one or more node terminals connected with the repeating installation itself, and decides path information of input-output data inputted/outputted into/from the repeating installation itself so that the respective repeating installations manage allocation of communication channels of the input-output data individually and dispersively. Therefore, processing load due to the path management in the repeating installations is reduced, and processing time required for the path management in the repeating installations is shortened. As a result, in the case where data are exchanged between node terminals belonging to respectively to different repeating installations, the communication data can be transmitted securely from an originating source node terminal to a specified destination node terminal.
In addition, a second aspect of the invention provides a communication method used in a communication system arranged by connecting plural repeating installations, to which one or more node terminals are connected, via a data transmission line, said communication method exchanging data between the node terminals, between the repeating installations or between the node terminals and repeating installations, said communication method comprising the steps of:
comparing and referring, in each repeating installation, to another path information, where use/free state of plural channels of the other repeating installations other than the repeating installation itself is described, comprised in communication data received by the other repeating installations and use/free state of channels corresponding to the one or more node terminals connected with the repeating installation itself;
deciding, in each repeating installation, path information of input-output data inputted/outputted into/from the repeating installation itself;
generating, in each repeating installation, output side path information of the repeating installation itself where the use/free state of the channels of the repeating installation itself is described; and
transmitting the communication data including the generated output side path information of the repeating installation itself to the other repeating installations other than the repeating installation itself;
whereby each repeating installation individually and dispersively manages allocation of communication channels of the input-output data.
According to the second aspect, instead of a central management of communication paths between the repeating installations using a conventional central managing device, in the plural repeating installations, a repeating installation compares and refers to another path information where use/free state of plural channels of the other repeating installations is described comprised in communication data received by the other repeating installations other than the repeating installation itself and use/free state of channels corresponding to the one or more node terminals connected with the repeating installation itself, and decides path information of input-output data inputted/outputted into/from the repeating installation itself and generates output side path information of the repeating installation itself where the use/free state of the channels of the repeating installation itself is described as well and transmits the communication data including the generated output side path information of the repeating installation to the other repeating installations other than the repeating installation itself so that the respective repeating installation manage allocation of communication channels of the input-output data individually and dispersively. Therefore, processing load due to the path management in the repeating installations is reduced, and processing time required for the path management in the repeating installations is shortened. As a result, even in the case where data are exchanged between node terminal belonging respectively to different repeating installations, the communication data can be transmitted securely from an originating node terminal to a specified destination node terminal.
Further, it is the point of a third aspect of the invention that the output side path information of the repeating installation itself is generated, based on the use/free state of plural channels of the other repeating installations other than the repeating installation itself described in the other path information, by updating corresponding channels in the other path information from use state to free state in the case where data output whose destination is a node terminal connected with the repeating installation itself exist, and by updating prescribed channels in free states in the other path information to be in use state in the case where data input whose originating source is a node terminal connected with the repeating installation itself.
According to the third aspect, the output side path information of the repeating installation itself is generated based on the use/free state of plural channels of the other repeating installations described in the other path information such that in the case where data output whose destination is a node terminal connected with the repeating installation itself exist, corresponding channels in the other path information in use state are updated to be in free state, whereas in the case where data input whose originating source is a node terminal connected with the repeating installation itself, prescribed channels in free states in the other path information are updated to be in use state.
Furthermore, it is the point of a fourth aspect of the invention that in the case where data input whose originating source is a node terminal connected with the repeating installation itself exist, and a destination of the data input is a node terminal connected with the repeating installation itself, decision of paired pieces of the path information corresponding to the paired node terminals is not prevented.
According to the fourth aspect of the present invention, in the case where data input whose originating source is a node terminal connected with the repeating installation itself exist and a destination of the data input is a node terminal connected with the repeating installation itself, decision of paired pieces of the path information corresponding to the paired node terminals is not prevented.
Further, a fifth aspect of the invention provides a communication method used in a communication system arranged by connecting plural repeating installations, to which one or more node terminals are connected, via a data transmission line, said communication method exchanging data between the node terminals, between the repeating installations or between the node terminals and repeating installations, said communication method comprising the steps of:
comparing and referring, in each repeating installation, to another path information, where use/free state of plural channels of the other repeating installations other than the repeating installation itself is described, comprised in communication data received by the other repeating installations and use/free state of channels corresponding to the one or more node terminals connected with the repeating installation itself; and
deciding, in each repeating installation, path information of input-output data inputted/outputted into/from the repeating installation itself, based on as to whether or not priority data having high priority whose destination is a node terminal connected with the repeating installation itself exist in the communication data;
whereby each repeating installations individually and dispersively manage allocation of communication channels of the input-output data.
Therefore, processing load due to the path management in the repeating installations is reduced, and processing time required for the path management in the repeating installations is shortened. As a result, in the case where priority data having high priority whose destination is a node terminal connected with the repeating installation itself exist, when channels corresponding to the node terminal as the destination are given priority in allocation to the priority data, the extremely practical communication method can be realized.
In addition, it is the point of a sixth aspect of the invention that when priority data having high priority whose destination is a node terminal connected with the repeating installation itself exist in the communication data, path information is decided so that the priority data are given priority in interruption and output via a desired channel regardless of use/free state of channels corresponding to the node terminal as the destination.
According to the sixth aspect, when priority data having high priority whose destination is a node terminal connected with the repeating installation itself exist in the communication data, path information is decided so that the priority data are given priority in interruption and output via a desired channel regardless of use/free state of channels corresponding to the node terminal as the destination. Therefore, the extremely practical communication method which faithfully reflects priority can be realized.
Further, a seventh aspect of the invention provides a communication system comprising plural repeating installations connected via a data transmission line, each repeating installation connected with one or more node terminals, said communication system exchanging data between the node terminals, between the repeating installations or between the node terminals and repeating installations, said each repeating installation comprising:
a receiving unit receiving communication data including another path information where use/free state of plural channels of the other repeating installations other than the repeating installation itself is described, from the other repeating installation;
a state judging unit judging use/free state of channels corresponding to one or more node terminals connected with the repeating installation itself; and
a path information deciding unit comparing and referring to another path information comprised in the communication data received by the receiving unit and the use/free state of the channels corresponding to the one or more node terminals connected with the repeating installation itself judged by the state judging unit to decide path information of input-output data inputted/outputted into/from the repeating installation itself;
whereby the path information deciding unit individually and dispersively manages allocation of communication channels for the input-output data.
According to the seventh aspect, first the receiving unit provided to the plural repeating installations receives the communication data including another path information where use/free state of the plural channels of the other repeating installations is described from the repeating installations other than the repeating installation itself. Meanwhile, the state judging unit judges use/free state of channels corresponding to one or more node terminals connected with the repeating installation itself. The path information deciding unit compares and refers to another path information comprised in the communication data received by the receiving unit and the use/free state of the channels corresponding to the one or more node terminals connected with the repeating installation itself judged by the state judging unit so as to decide path information of input-output data inputted/outputted into/from the repeating installation itself. As a result, the allocation of the communication channels for the input-output data is managed individually and dispersively.
Namely, instead of the central management of the communication paths between the repeating installations using a conventional central managing device, since the plural repeating installations manage the allocation of the communication channels for the input-output data inputted/outputted into/from the repeating installation itself individually and dispersively, processing load due to the path management in the repeating installations is reduced, and processing time required for the path management in the repeating installations is shortened. As a result, in the case where even in the case where data are exchanged between node terminals belonging respectively to different repeating installations, the communication data can be transmitted securely from an originating source node terminal to a specified destination node terminal.
Furthermore, an eighth aspect of the invention provides a communication system comprising plural repeating installations connected via a data transmission line, each repeating installation connected with one or more node terminals, said communication system exchanging data between the node terminals, between the repeating installations or between the node terminals and repeating installations, said each repeating installation comprising:
a receiving unit receiving communication data including another path information where use/free state of plural channels of the other repeating installations other than a repeating installation itself is described, from the other repeating installation;
a state judging unit judging use/free state of channels corresponding to one or more node terminals connected with the repeating installation itself;
a path information deciding unit comparing and referring to another path information comprised in the communication data received by the receiving unit and the use/free state of the channels corresponding to the one or more node terminals connected with the repeating installation itself judged by the state judging unit to decide path information of input-output data inputted/outputted into/from the repeating installation itself;
a self path information generating unit comparing and referring to another path information comprised in the communication data received by the receiving unit and the use/free state of the channels corresponding to the one or more node terminals connected with the repeating installation itself judged by the state judging unit to generate self output side path information where use/free state of the channels of the repeating installation itself is described; and
a transmitting unit transmitting the communication data including the self output side path information generated by the self path information generating unit to the other repeating installations other than the repeating installation itself;
whereby the path information deciding unit individually and dispersively manages allocation of communication channels for the input-output data.
According to the eighth aspect, first the receiving unit receives communication data including another path information where use/free state of plural channels of repeating installations other than a repeating installation itself from the repeating installation itself, the state judging unit judges use/free state of channels corresponding to one or more node terminals connected with the repeating installation itself. The path information deciding unit comparing and referring to another path information comprised in the communication data received by the receiving unit and the use/free state of the channels corresponding to the one or more node terminals connected with the repeating installation itself judged by the state judging unit so as to decide path information of input-output data inputted/outputted into/from the repeating installation itself. As a result, the allocation of the communication channels for the input-output data is managed individually and dispersively. Moreover, the self path information generating unit compares and refers to another path information comprised in the communication data received by the receiving unit and the use/free state of the channels corresponding to the one or more node terminals connected with the repeating installation itself judged by the state judging unit so as to generate self output side path information where use/free state of the channels of the repeating installation itself is described. Accordingly the transmitting unit transmits the communication data including the self output side path information generated by the self path information generating unit to the other repeating installations other than the repeating installation itself.
In such a manner, instead of the central management of the communication paths between the repeating installations using a conventional central managing device, since the plural repeating installations manage the allocation of the communication channels for the input-output data inputted/outputted into/from the repeating installation itself individually and dispersively, processing load due to the path management in the repeating installations is reduced, and processing time required for the path management in the repeating installations is shortened. As a result, in the case where even in the case where data are exchanged between node terminals belonging respectively to different repeating installations, the communication data can be transmitted securely from an originating source node terminal to a specified destination node terminal.
Further, it is the point of a ninth aspect of the invention that the self path information generating unit generates the self output side path information, based on the use/free state of plural channels of the other repeating installations described in the other path information, by updating corresponding channels in another path information from use state to free state in the case where data output whose destination is a node terminal connected with the repeating installation itself exist, and by updating prescribed channels in free states in the other path information to be in use state in the case where data input whose originating source is a node terminal connected with the repeating installation itself.
According to the ninth aspect, the self path information generating unit generates the self output side path information based on the use/free state of plural channels of the other repeating installations described in the other path information such that in the case where data output whose destination is a node terminal connected with the repeating installation itself exist, corresponding channels in another path information in use state are updated to be in free state, whereas in the case where data input whose originating source is a node terminal connected with the repeating installation itself, prescribed channels in free states in the other path information are updated to be in use state.
Further, it is the point of a tenth aspect of the invention that in the case where data input whose originating source is a node terminal connected with the repeating installation itself exist, and a destination of the data input is a node terminal connected with the repeating installation itself, decision of paired pieces of the path information corresponding to the paired node terminals is not prevented.
According to the tenth aspect, in the case where data input whose originating source is a node terminal connected with the repeating installation itself exist and a destination of the data input is a node terminal connected with the repeating installation itself, decision of paired pieces of the path information corresponding to the paired node terminals is not prevented.
In addition, an eleventh aspect of the invention, a communication method used in a communication system arranged by connecting plural repeating installations, to which one or more node terminals are connected, via a data transmission line, said communication method exchanging data between the node terminals, between the repeating installations or between the node terminals and repeating installations, said communication method comprising the steps of:
a requesting from a path request repeating installation requesting transmission of communication data in the plural repeating installations to repeating installations existing within a request path range from an originating source to destination of the communication data to return path information containing free state of respective output side paths;
selecting, in the path request repeating installation, definite paths through which the communication data pass based on the respective path information returned from the repeating installations existing within the request path range;
transmitting the definite path information containing the selected definite paths from the path request repeating installation to the repeating installations existing within the request path range;
revising the respective path information, in the repeating installations existing within the request path range, based on the definite path information received from the path request repeating installation to secure pass paths for the communication data prior to transmission of the communication data from the path request repeating installation.
According to the eleventh aspect, a path request repeating installation requesting transmission of communication data in the plural repeating installations first requests repeating installations existing within a request path range from an originating source to destination of the communication data to return path information containing free state of respective output side paths. Next, the path request repeating installation selects definite paths through which the communication data pass based on the respective path information returned from the repeating installations existing within the request path range. Then, the path request repeating installation transmits the definite path information containing the selected definite paths to the repeating installations existing within the request path range.
Meanwhile, the repeating installations existing within the request path range revise the respective path information based on the definite path information received from the path request repeating installation.
As a result, prior to transmission of the communication data from the path request repeating installation, pass paths for the communication data can be secured, and the processing procedure between the repeating installations is simplified when the pass paths for the communication data are secured. As a result, even in the case where data are exchanged between node terminal belonging respectively to different repeating installations, the communication data can be transmitted securely from an originating source node terminal to a destination node terminal.
Further, it is the point of a twelfth aspect of the invention, to further comprises the steps of:
obtaining, in the path request repeating installation, common free paths between the path information in the repeating installations existing within the request path range by performing logical operation of the respective path information returned from the repeating installations existing within the request path range; and
selecting, in the path request repeating installation, definite paths through which the communication data pass from the obtained common free paths between the path information of the repeating installations existing within the request path range.
According to the twelfth aspect, the path request repeating installation requests the repeating installations existing within the request path range from an originating source to destination of the communication data to return the path information containing free state of the respective output side paths, obtains common free paths between the path information in the repeating installations existing within the request path range by performing logical operation of the respective path information returned from the repeating installations existing within the request path range, selects definite paths through which the communication data pass from the obtained common free paths, and transmits the definite path information containing the selected definite paths to the repeating installations existing within the request path range.
Furthermore, it is the point of a thirteenth aspect the invention that the repeating installations existing within the request path range update the selected definite paths in free state to be in use state based on the definite path information received from the path request repeating installation to revise the respective path information.
According to the thirteenth aspect, the repeating installations existing within the request path range update the selected definite paths in free state to be in use state based on the definite path information received from the path request repeating installation so as to revise the respective path information.
Further, a fourteenth aspect of the invention provides communication method used in a communication system arranged by connecting plural repeating installations, to which one or more node terminals are connected, via a data transmission line, said communication method exchanging data between the node terminals, between the repeating installations or between the node terminals and repeating installations, said communication method comprising the steps of:
requesting from a path request repeating installation requesting transmission of communication data in the plural repeating installations to repeating installations existing within a request path range from an originating source to destination of the communication data to return path information containing free state of respective output side paths;
obtaining, in the path request repeating installation, common free paths between the path information in the repeating installations existing within the request path range by performing logical operation of the respective path information returned from the repeating installations existing within the request path range;
selecting, in the path request repeating installation, definite paths through which the communication data pass from the obtained common free paths between the path information of the repeating installations existing within the request path range;
transmitting the definite path information containing the selected definite paths from the path request repeating installation to the repeating installations existing within the request path range;
updating, in the repeating installations existing within the request path range, the selected definite paths in free state to be in use state based on the definite path information received from the path request repeating installation to revise the respective path information and thus securing pass paths for the communication data prior to transmission of the communication data from the path request repeating installation.
According to the fourteenth aspect, the path request repeating installation first requests repeating installations existing within a request path range from an originating source to destination of the communication data to return path information containing free state of respective output side paths. Next, the path request repeating installation obtains common free paths between the path information in the repeating installations existing within the request path range by performing logical operation of the respective path information returned from the repeating installations existing within the request path range, and selects definite paths through which the communication data pass from the obtained common free paths. Then, the path request repeating installation transmits the definite path information containing the selected definite path to the repeating installations existing within the request path range.
Meanwhile, the repeating installations existing within the request path range update the selected definite paths in free state to be in use state based on the definite path information received from the path request repeating installation so as to revise the respective path information.
As a result, prior to transmission of the communication data from the path request repeating installation, pass paths for the communication data can be secured, and when the pass paths for the communication data, the communication procedure between the repeating installations is simplified. As a result, even in the case where data are exchanged between node terminal belonging respectively to different repeating installations, the communication data can be transmitted securely from an originating source node terminal to a specified destination node terminal.
In addition, a fifteenth aspect of the invention provides communication system comprising plural repeating installations connected via a data transmission line, each repeating installation connected with one or more node terminals, said communication system exchanging data between the node terminals, between the repeating installations or between the node terminals and repeating installations, wherein
a path request repeating installation requesting transmission of communication data in the plural repeating installations comprising:
a path information return requesting unit requesting the repeating installations existing within the request path range from a transmission source to destination of the communication data to return path information containing free state of respective output side paths;
a selecting unit selecting definite paths through which the communication data pass based on the respective path information returned from the repeating installations existing within the request path range; and
a definite path information transmitting unit transmitting the definite path information containing the definite paths selected by the selecting unit to the repeating installations existing within the request path range; and
the respective repeating installations existing within the request path range comprising:
a definite path information receiving unit receiving the definite path information from the path request repeating installation; and
a path information revising unit revising the respective path information based on the definite path information received by the definite path information receiving unit;
whereby the respective repeating installations existing within the request path range secures pass paths of the communication data prior to transmission of the communication data from the path request repeating installation.
According to the fifteenth aspect, in the path request repeating installation, the path information return requesting unit requests the repeating installations existing within the request path range from a transmission source to destination of the communication data to return path information containing free state of respective output side paths. Next, the selecting unit selects definite paths through which the communication data pass based on the respective path information returned from the repeating installations existing within the request path range. Then, the definite path information transmitting unit transmits the definite path information containing the definite paths selected by the selecting unit to the repeating installations existing within the request path range.
Meanwhile, in the respective repeating installations existing within the request path range, the definite path information receiving unit receives the definite path information from the path request repeating installation. The path information revising unit revises the respective path information based on the definite path information received by the definite path information receiving unit.
As a result, prior to transmission of the communication data from the path request repeating installation, pass paths of the communication data can be obtained, and when the pass paths for the communication data are secured, the communication procedure between the repeating installations is simplified. As a result, even in the case where data are exchanged between node terminal belonging respectively to different repeating installations, the communication data can be transmitted securely from an originating source node terminal to a specified destination node terminal.
Further, it is the point of a sixteenth aspect of the invention that the path request repeating installation further comprises a free path operating unit obtaining common free paths between path information of the repeating installations existing within the request path range by performing the logical operation on the respective path information returned from the repeating installations existing within the request path range; and the selecting unit selecting definite paths through which the communication data pass from the common free paths between the path information of the repeating installations existing within the request path range obtained by the free path operating unit.
According to the sixteenth aspect, in the path request repeating installation, the free path operating unit obtains common free paths between path information of the repeating installations existing within the request path range by performing the logical operation on the respective path information returned from the repeating installations existing within the request path range. The selecting unit selects definite paths through which the communication data pass from the common free paths between the path information of the repeating installations existing within the request path range obtained by the free path operating unit.
Further, it is the point of a seventeenth aspect of the invention that the path information revising unit updates the selected definite paths in free state to be in use state based on the definite path information received by the definite path information receiving unit so as to revise the respective path information.
According to the seventeenth aspect, the path information revising unit updates the selected definite paths in free state to be in use state based on the definite path information received by the definite path information receiving unit so as to revise the respective path information.
In addition, an eighteenth aspect of the invention provides a communication system comprising plural repeating installations connected via a data transmission line, each repeating installation connected with one or more node terminals, said communication system exchanging data between the node terminals, between the repeating installations or between the node terminals and repeating installations, wherein
a path request repeating installation requesting transmission of communication data in the plural repeating installations comprising:
a path information return requesting unit requesting the repeating installations existing within the request path range from an originating source to destination of the communication data to return path information containing free state of respective output side paths;
a free path operating unit obtaining common free paths between path information of the repeating installations existing within the request path range by performing the logical operation on the respective path information returned from the repeating installations existing within the request path range;
a selecting unit selecting definite paths through which the communication data pass from the common free paths between the path information of the repeating installations existing within the request path range obtained by the free path operating unit; and
a definite path information transmitting unit transmitting the definite path information containing the definite paths selected by the selecting unit to the repeating installations existing within the request path range; and
the respective repeating installations existing within the request path range comprising:
a definite path information receiving unit receiving the definite path information from the path request repeating installation; and
a path information revising unit updating the definite paths selected by the selecting unit in free state to be in use state based on the definite path information received by the definite path information receiving unit so as to revise the respective path information;
whereby the respective repeating installations existing within the request path range secure pass paths of the communication data prior to transmission of the communication data from the path request repeating installation.
According to the eighteenth aspect, in the path request repeating installation, first the path information return requesting unit requests the repeating installations existing within the request path range from an originating source to destination of the communication data to return path information containing free state of respective output side paths. Next, the free path operating unit obtains common free paths between path information of the repeating installations existing within the request path range by performing the logical operation on the respective path information returned from the repeating installations existing within the request path range. Moreover, the selecting unit selects definite paths through which the communication data pass from the common free paths obtained by the free path operating unit. Then, the definite path information transmitting unit transmits the definite path information containing the definite paths selected by the selecting unit to the repeating installations existing within the request path range.
Meanwhile in the respective repeating installations existing within the request path range, the definite path information receiving unit receives the definite path information from the path request repeating installation. Accordingly, the path information revising unit updates the definite paths selected by the selecting unit in free state to be in use state based on the definite path information received by the definite path information receiving unit so as to revise the respective path information.
As a result, prior to transmission of the communication data from the path request repeating installation, pass paths of the communication data can be obtained, and when the pass paths for the communication data are secured, the communication procedure between the repeating installations is simplified. As a result, even in the case where data are exchanged between node terminal belonging respectively to different repeating installations, the communication data can be transmitted securely from an originating source node terminal to a specified destination node terminal.
Further, a nineteenth aspect of the invention provides communication method used in a communication system arranged by connecting plural repeating installations, to which one or more node terminals are connected, via a data transmission line, said communication method exchanging data between the node terminals, between the repeating installations or between the node terminals and repeating installations, said communication method comprising the steps of:
returning common free paths between output side path information of the respective repeating installations, which are obtained by referring to path information containing free state of the output side paths of the repeating installations existing within a request path range from an originating source to destination of the communication data, from the repeating installations existing within the request path range to the path request repeating installation requesting transmission of communication data in the plural repeating installations;
selecting, in the path request repeating installation, definite paths through which the communication data pass from the returned common free paths between the output side path information of the repeating installations;
transmitting the definite path information containing the selected definite paths to the repeating installations existing within the request path range; and
revising, in the respective repeating installations existing within the request path range, the respective path information based on the definite path information received from the path request repeating installation to secure pass paths for the communication data prior to transmission of the communication data from the path request repeating installation.
According to the nineteenth aspect, a path request repeating installation requesting transmission of communication data in the plural repeating installations first returns common free paths between output side path information of the respective repeating installations, which are obtained by referring to path information containing free state of the output side paths of the repeating installations existing within a request path range from an originating source to destination of the communication data, from the repeating installations existing within the request path range to the path request repeating installation. Next, the path request repeating installation selects definite paths through which the communication data pass from the returned common free paths between the output side path information of the repeating installations. Then, the path request repeating installation transmits the definite path information containing the selected definite paths to the repeating installations existing within the request path range.
Meanwhile, the respective repeating installations existing within the request path range revise the respective path information based on the definite path information received from the path request repeating installation.
As a result, prior to transmission of the communication data from the path request repeating installation, pass paths for the communication data can be secured, and when the pass paths for the data communication are secured, the communication procedure between the repeating installations is simplified. As a result, even in the case where data are exchanged between node terminal belonging respectively to different repeating installations, communication data can be transmitted securely from an originating source node terminal to a destination node terminal.
Furthermore, a twentieth aspect of the invention provides a communication method used in a communication system arranged by connecting plural repeating installations, to which one or more node terminals are connected, via a data transmission line, said communication method exchanging data between the node terminals, between the repeating installations or between the node terminals and repeating installations, said communication method comprising the steps of:
returning common free paths between output side path information of the respective repeating installations, which are obtained by referring to path information containing free state of output side paths of the repeating installations existing within a request path range from an originating source to destination of the communication data, from the repeating installations existing within the request path range to the path request repeating installation requesting transmission of communication data in the plural repeating installations;
selecting, in the path request repeating installation, definite paths through which the communication data pass from the returned common free paths between the output side path information of the repeating installations;
transmitting the definite path information containing the selected definite paths to the repeating installations existing within the request path range;
updating, in the repeating installations existing within the request path range, the selected definite paths in free state to be in use state based on the definite path information received from the path request repeating installation to revise the respective path information, thereby to secure pass paths for the communication data prior to transmission of the communication data from the path request repeating installation.
According to the twentieth aspect, first the path request repeating installation requesting transmission of communication data in the plural repeating installations returns common free paths between output side path information of the respective repeating installations, which are obtained by referring to path information containing free state of output side paths of the repeating installations existing within a request path range from an originating source to destination of the communication data, from the repeating installations existing within the request path range to the path request repeating installation. Next, the path request repeating installation selects definite paths through which the communication data pass from the common free paths between the output side path information returned from the repeating installations existing within the request path range. Then, the path request repeating installation transmits the definite path information containing the selected definite paths to the repeating installations existing within the request path range.
Meanwhile, the respective repeating installations existing within the request path range update the selected definite paths in free state to be in use state based on the definite path information received from the path request repeating installation so as to revise the respective path information.
As a result, prior to transmission of the communication data from the path request repeating installation, pass paths for the communication data are secured, and when the path paths for the communication data are secured, and the communication procedure between the repeating installations is simplified. As a result, even in the case where data are exchanged between node terminals belonging respectively to different repeating installations, the communication data can be transmitted securely from an originating source node terminal to a destination node terminal.
Further, a twenty-first aspect of the invention provides a communication system comprising plural repeating installations connected via a data transmission line, each repeating installation connected with one or more node terminals, said communication system exchanging data between the node terminals, between the repeating installations or between the node terminals and repeating installations, wherein
a path request repeating installation requesting transmission of communication data in the plural repeating installations comprising:
a path information return requesting unit requesting to return common free paths between output side path information of the respective repeating installations, which are obtained by referring to path information containing free state of the output side paths of the repeating installations existing within a request path range from an originating source to destination of the communication data, from the repeating installations existing within the request path range to the path request repeating installation;
a selecting unit selecting definite paths through which the communication data pass based on the respective path information returned from the repeating installations existing within the request path range; and
a definite path information transmitting unit transmitting the definite path information containing the selected definite paths selected by the selecting unit to the repeating installations existing within the request path range; and
the respective repeating installations existing within the request path range comprising:
a definite path information receiving unit receiving the definite path information from the path request repeating installation; and
a path information revising unit revising the respective path information based on the definite path information received by the definite path information receiving unit;
whereby the respective repeating installations existing within the request path range secure pass paths for the communication data prior to transmission of the communication data from the path request repeating installation.
According to the twenty-first aspect, in the path request repeating installation, first the path information return requesting unit requests to return common free paths between output side path information of the respective repeating installations, which are obtained by referring to path information containing free state of the output side paths of the repeating installations existing within a request path range from an originating source to destination of the communication data, from the repeating installations existing within the request path range to the path request repeating installation. Next, the selecting unit selects definite paths through which the communication data pass from the common free paths between the output side path information of the repeating installations returned from the repeating installations existing within the request path range. Then, the definite path information transmitting unit transmits the definite path information containing the selected definite paths selected by the selecting unit to the repeating installations existing within the request path range.
Meanwhile, in the respective repeating installations existing within the request path range, the definite path information receiving unit receives the definite path information from the path request repeating installation. The path information revising unit revises the respective path information based on the definite path information received by the definite path information receiving unit.
As a result, prior to transmission of the communication data from the path request repeating installation, pass paths for the communication data can be secured, and the communication procedure between the repeating installations is simplified. As a result, even in the case where data are exchanged between node terminals belonging respectively to different repeating installations, the communication data can be transmitted securely from an originating source node terminal to a destination node terminal.
Further, a twenty-second aspect of the invention provides a communication system comprising plural repeating installations connected via a data transmission line, each repeating installation connected with one or more node terminals, said communication system exchanging data between the node terminals, between the repeating installations or between the node terminals and repeating installations, wherein
a path request repeating installation requesting transmission of communication data in the plural repeating installations comprising:
a path information return requesting unit requesting to return common free paths between output side path information of the respective repeating installations, which are obtained by referring to path information containing free state of output side paths of the repeating installations existing within a request path range from an originating source to destination of the communication data, from the repeating installations existing within the request path range to the path request repeating installation;
a selecting unit selecting definite paths through which the communication data pass based on the respective path information returned from the repeating installations existing within the request path range; and
a definite path information transmitting unit transmitting the definite path information containing the definite paths selected by the selecting unit to the repeating installations existing within the request path range; and
the respective repeating installations existing within the request path range comprising:
a definite path information receiving unit receiving the definite path information from the path request repeating installation; and
a path information revising unit updating the definite paths selected by the selecting unit in free state to be in use state based on the definite path information received by the definite path information receiving unit so as to revise the respective path information;
whereby the respective repeating installations existing within the request path range secure pass paths for the communication data prior to transmission of the communication data from the path request repeating installation.
According to the twenty-second aspect, in the path request repeating installation, first the path information return requesting unit requests to return common free paths between output side path information of the respective repeating installations, which are obtained by referring to path information containing free state of output side paths of the repeating installations existing within a request path range from an originating source to destination of the communication data, from the repeating installations existing within the request path range to the path request repeating installation. Next, the selecting unit selects definite paths through which the communication data pass from the common free paths between the output side path information of the repeating installations returned from the repeating installations existing within the request path range. Then, the definite path information transmitting unit transmits the definite path information containing the definite paths selected by the selecting unit to the repeating installations existing within the request path range.
Meanwhile, in the respective repeating installations existing within the request path range comprise, the definite path information receiving unit receives the definite path information from the path request repeating installation. The path information revising unit updates the definite paths selected by the selecting unit in free state to be in use state based on the definite path information received by the definite path information receiving unit so as to revise the respective path information.
As a result, prior to transmission of the communication data from the path request repeating installation, pass paths for the communication data can be secured, and the communication procedure between the repeating installations is simplified. As a result, even in the case where data are exchanged between node terminals belonging respectively to different repeating installations, the communication data can be transmitted securely from an originating source node terminal to a destination node terminal.